For years, I have used the + symbol to filter out accounts I sign up for. The idea is simple if your email is the following:
Add a plus to your email address like this:
That way I can create a filter in my inbox. Perhaps I don't want my book club email to go into my main inbox but to go into a special folder instead. I can also see if A1 Book Club is selling my email address to others. Of course this is just an example, you can add anything after the + to help you understand where this email is coming from.
As a teacher, I am always signing up for freebies, promotions, etc, but I don't care for the email that comes to my inbox after doing so. After doing some tests, I have learned that the above email conventions works for Google Education email as well.
Bye bye unwanted email.